Chemistry of iron in contact with liquid metallic hydrogen and carbon at extreme conditions

We will exploit the new High Power Laser Facility (HPLF) at ID-24 to determine the chemical reactivity of iron with hydrogen and/or carbon at extreme pressure and temperature conditions on nanosecond timescale. Using a laser-driven dynamic compression approach, we will compress Fe-doped polystyrene samples, reaching conditions where carbon and hydrogen separate (~150 GPa, 5000 K). The element-specific XANES probe will then record how the iron nanoparticles react with either (presumably metallic) H and/or insulating C. This experiment, which is currently only possible at ESRF, will be a door-opener to access element-specific chemistry in dynamic compression experiments. If successful, our proof-of-principle study will enable various follow-up experiments with science cases ranging from geophysics, giant impacts and properties of exoplanets to dynamic synthesis of room-temperature superconductors.